Attention is being focused on connections between identified afferent neurons that innervate local sensory structures on the exoskeleton of crayfish, and identified interneurons in the central nervous system. We have already shown that there is considerable precision in the replication of these connections from one individual animal to the next, although the pattern is less fixed than that between strictly central elements, that new connections by sensory elements are added during development, and regenerating sensory nerves make "correct" connections. We are now tracing the central routes taken by individual sensory axons, and analyzing the multiple connections made by each one upon different central interneurons. We also hope to establish a basis for directional sensitivity in this sensory system.